With the rapid development of displaying technology, display panels show a development trend towards high integration and low cost more and more. The Gate Driver on Array (GOA) technique integrates Thin Film Transistor (TFT) gate switching circuits on an array substrate of a display panel, thus forming scan driving for the display panel, and accordingly saving the wiring space of a bonding area of a gate Integrated Circuit (IC) and a Fan-out area, which not only can reduce product cost in two aspects of material expenses and manufacturing process, but also can achieve symmetry on two sides of the display panel and a beautiful design of narrow bezel. And such integration technique can also eliminate bonding process in a gate scanning line direction, thus improving the productivity and yield rate.
A typical gate driving circuit comprises a plurality of shift registers in cascaded stages, wherein driving signal output terminals of shift registers in respective stages are connected to corresponding gate lines respectively, so that scan signals can be inputted by shift registers in respective stages to gate lines in respective rows on the display panel in sequence. In the existing shift register, when outputting of the scan signal is completed, usually a signal at a clock signal terminal is supplied to a pull-down node through a switching transistor to charge the pull-down node, so that the pull-down node then controls a switching transistor to discharge a pull-up node. However, in practical operation of the shift register, a voltage at the pull-down node is usually decreased due to a leakage current of other switching transistors connected with the pull-down node, which weakens the discharge capability of the switching transistor that discharges the pull-up node, thereby in turn a relative large noise in the outputted scan signal.